1. Technical Field
The present invention is concerned with comparing one pattern with another, and is of particular interest in the comparison of two-dimensional patterns such as visual images, although applicable also to one-dimensional patterns and patterns having three or more dimensions.
2. Related Art
Some techniques for analysis of images or other patterns where the pattern is compared with other parts of the same pattern are described in our earlier patent applications as follows.    European patent application 00301262.2 (publication No. 1126411);    International patent application PCT/GB01/00504 (publication No. WO 01/61648);    International patent application PCT/GB01/03802 (publication No. WO02/21446));    U.S. patent application Ser. No. 977,263/09 filed 16 Oct. 2001 (publication No. 20020081033);            as well as the following papers published by the inventor:            Stentiford F W M, “An estimator for visual attention through competitive novelty with application to image compression”, Proc. Picture Coding Symposium 2001, Seoul, 25-27 April, pp 101-104, 2001.    Stentiford F W M, “An evolutionary programming approach to the simulation of visual attention”, Proc. Congress on Evolutionary Computation 2001, Seoul, pp 851-858, 27-30 May 2001.
Methods and apparatus for comparing patterns are described in our earlier international patent application WO03/081532 and our co-pending international patent application WO2006/030173.